Update VMManager.cpp to not count paused time toward time played

Hopefully resolves #10497. Between each update to played time, we calculate the sum of the deltas between VM resume and pause in order to subtract that off from the total session (paused and unpaused) session time.

Thus, if someone pauses the emulator, that time spent paused will no longer be reflected in the GameList.

pcsx2/VMManager.cpp

@@ -124,6 +124,8 @@ namespace VMManager
 	static void LoadCoreSettings(SettingsInterface* si);
 	static void ApplyCoreSettings();
 	static void UpdateInhibitScreensaver(bool allow);
+	static void AccumulateSessionPlaytime();
+	static void ResetResumeTimestamp();
 	static void SaveSessionTime(const std::string& prev_serial);
 	static void ReloadPINE();
 
@@ -183,7 +185,8 @@ static float s_target_speed = 0.0f;
 static bool s_use_vsync_for_timing = false;
 
 // Used to track play time. We use a monotonic timer here, in case of clock changes.
-static u64 s_session_start_time = 0;
+static u64 s_session_resume_timestamp = 0;
+static u64 s_session_accumulated_playtime = 0;
 
 static bool s_screensaver_inhibited = false;
 
@@ -232,6 +235,16 @@ VMState VMManager::GetState()
 	return s_state.load(std::memory_order_acquire);
 }
 
+void VMManager::AccumulateSessionPlaytime()
+{
+	s_session_accumulated_playtime += static_cast<u64>(Common::Timer::GetCurrentValue()) - s_session_resume_timestamp;
+}
+
+void VMManager::ResetResumeTimestamp()
+{
+	s_session_resume_timestamp = static_cast<u64>(Common::Timer::GetCurrentValue());
+}
+
 void VMManager::SetState(VMState state)
 {
 	// Some state transitions aren't valid.
@@ -261,10 +274,16 @@ void VMManager::SetState(VMState state)
 
 		UpdateInhibitScreensaver(!paused && EmuConfig.InhibitScreensaver);
 
-		if (state == VMState::Paused)
+		if (paused)
+		{
 			Host::OnVMPaused();
+			AccumulateSessionPlaytime();
+		}
 		else
+		{
 			Host::OnVMResumed();
+			ResetResumeTimestamp();
+		}
 	}
 	else if (state == VMState::Stopping && old_state == VMState::Running)
 	{
@@ -2975,23 +2994,19 @@ void VMManager::SaveSessionTime(const std::string& prev_serial)
 	if (GSDumpReplayer::IsReplayingDump())
 		return;
 
-	const u64 ctime = Common::Timer::GetCurrentValue();
 	if (!prev_serial.empty())
 	{
 		// round up to seconds
 		const std::time_t etime =
-			static_cast<std::time_t>(std::round(Common::Timer::ConvertValueToSeconds(ctime - s_session_start_time)));
+			static_cast<std::time_t>(std::round(Common::Timer::ConvertValueToSeconds(std::exchange(s_session_accumulated_playtime, 0))));
 		const std::time_t wtime = std::time(nullptr);
 		GameList::AddPlayedTimeForSerial(prev_serial, wtime, etime);
 	}
-
-	s_session_start_time = ctime;
 }
 
 u64 VMManager::GetSessionPlayedTime()
 {
-	const u64 ctime = Common::Timer::GetCurrentValue();
-	return static_cast<u64>(std::round(Common::Timer::ConvertValueToSeconds(ctime - s_session_start_time)));
+	return static_cast<u64>(std::round(Common::Timer::ConvertValueToSeconds(s_session_accumulated_playtime)));
 }
 
 #ifdef _WIN32